As used herein, the following terms have the meanings ascribed:
"Filament or filaments" refer to fibrous strands of extreme or indefinite length. In contrast, "staple fibers" are fibrous strands of definite and short lengths.
"Yarn" refers to a continuous assemblage of filaments twisted or laid together.
"Commingling" refers to blending or mixing together of the filaments of two or more yarns.
"Multicolor yarn" refers to an assemblage of two or more filaments or groups of filaments which are differently colored or colorable with respect to each other.
"Singles yarn" means the simplest unit of yarn suitable for use in, for example, weaving and knitting. One end of BCF (bulked continuous filament) is a singles yarn.
"Space dyed appearance" refers to the effect produced by dyeing yarn at irregular intervals with more than one color along its length.
Yarns made from differently colored or colorable filaments and methods for making them are known. One example of such yarns are heather type yarns. Heather yarns display muted, mixed or diffused color.
Certain other multicolor yarn displays mutually distinguishable colors. For example, U.S. Pat. No. 5,251,363 to Gerhards et al. describes a method and apparatus for producing multicolored crimped yarns. The method includes spinning a plurality of differently colored groups of filaments, subjecting the filaments of each group to a treatment liquid, and then combining the filaments to form respective strands. Each strand is then subjected to an air entangling process, then stretched and the strands are thereafter combined in a thermo-pneumatic texturing process.
U.S. Pat. No. 5,220,778 to Flachmueller et al. describes a method for the production of untwisted yarns from at least two fibril bundles. Intermediate steps which are introduced between the main conventional steps of spinning, stretching and texturing allow the reciprocal position of the individual fibril bundles resulting from the arrangement of the spinnerets to be retained through the process. The patents states that a non-positively acting false twister for each individual fibril bundle, whose strength or thickness can be varied, also makes it possible to vary the mixing of the fibrils of the individual bundles in their contact zones.
U.S. Pat. No. 4,408,376 to Hatcher et al. pertains to the drawing of a plurality of yarns about draw rolls in adjacent untwisted relation. The invention is described as having particular application to the processing of yarn ends, each of which has a different color, which ends are to be subsequently twisted into a single yarn having uniform color properties throughout its length.
U.S. Pat. No. 4,025,595 to Mirhej describes that a range of continuous mixed filament texturing feed yarns will provide a range of fabrics having advantageous mixed filament characteristics that can be prepared in a single process when at least two different continuous filament yarns are co-spun and separately entangled. The process is described as providing yarns which will produce a whole spectrum of mixed filament effects in a fabric ranging from high contrast/high directionality to low contrast/low directionality.
U.S. Pat. No. 3,780,516 to Kimbrell describes a process for forming a yarn wherein a plurality of yarn ends pass from their respective yarn packages, are each wrapped about a common feed roll, passed from the feed roll through a heating zone, passed from the heating zone to a common heated draw roll, are wrapped about the heated draw roll and passed from the heated draw roll through apparatus for bringing the yarn ends into contact with one another in a pre-selected arrangement to form a resulting yarn which has improved properties caused by wrapping a selected one of the yarn ends about the heated draw roll a number of turns which is greater than the common number of turns the other yarn ends are wrapped about the draw roll.
U.S. Pat. No. 5,148,586 to Coons describes a process and apparatus for producing a yarn with a novel heather appearance.
Co-pending U.S. application Ser. No. 08/311,660 describes a process for making distinct color effects in staple yarn.